title: Noise exposure as a risk factor of cardiovascular diseases in workers.
abstract: BACKGROUND
  Workers in different jobs are exposed to noise, which can affect hearing loss and sleep disturbance in the long term. Excessive noise exposure may lead to increased blood pressure, reduced efficiency, and increased absenteeism.
  
  
  METHODS
  In this case-control study, 80 workers were studied in terms of noise exposure and blood pressure. Noise exposure was measured by SEL 440 sound level meters according to ISO 1996 standard. Blood pressure of the case and control groups was measured in workplace, under standard circumstances, using ALPK2 mercury sphygmomanometer during physical examination. Data were analyzed by t-test and Pearson's correlation coefficient.
  
  
  RESULTS
  Mean level of noise was 95.21 ± 2.56 db, which was significantly higher than permitted limit of 85 db (ACGIH 2009) (P < 0.01). Diastolic blood pressure was normal in 28.8% and high in 50.1%, and between these in 21.1% of workers. Mean difference of systolic blood pressure in two studied groups (P < 0.01) was meaningful. However, mean difference of diastolic blood pressure was not significant in two studied groups (P > 0.05). There was a positive and weak relationship between noise and systolic blood pressure (r = 0.28, P < 0.006).
  
  
  CONCLUSIONS
  Prolonged exposure to industrial noise is related with high blood pressure as a risk factor of cardiovascular diseases. Therefore, it is recommended that training programs be held for workers, preventive measures for noise exposure at workplace be taken, blood pressure of workers be attended to and special care be given to workers with a history of hypertension.
authors.affiliation: Department of Occupational Health, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hossein Ali
authors.initials: HA
authors.lastname: Yousefi Rizi
authors.forename: Akbar
authors.initials: A
authors.lastname: Hassanzadeh
keywords: Cardiovascular diseases; Isfahan industry; hypertension; noise; occupational exposure; workers